1. Glue 2 2x4s to the left and right bottom of bookcase #1 using polyurethane glue and clamps.

2. Mount 4 2 inch swivel casters to the 2 x 4s using #10 x 1 1/2 inch screws; one in each corner of the bookcase. Be careful that the cast swivals completely. Caster wheel should protrude 1 inch or so below bottom of the bookcase skirt

3. Lay bookcase #1 on its side and set bookcase #2 on top. Align the edges.

4. Drill 6 holes to accommodate 1/4 20 x 9/16 T-nuts. Two near bottom of bookcase, two near top of bookcase and two near the middle. Insert t-nuts and bolt the bookcases together using 1/4 20 x 1 1/2 inch Flathead screws.

5. Set bookcase upright. (see note)

6. Mount hinges to door jam or wall

7. Mount hinges to Billy Bookcase #2 using t-nuts and 1/4 20 x 1" screws in appropriate location to match hinges from previous step. Hinge end of bookcase will have to be temporarily shimmed up to level the top as the hinges are installed. Bookcase should open easily and may need latch to hold it closed as you floor may not be level.

NOTE: Use caution from step 5 onwards as bookcases are unstable until hinges are installed. It is best to use 2 persons at this point.